Support structure



Jan. 25, 1966 A. D. JOHNSON 3,231,777

SUPPORT STRUCTURE Filed Dec. 15, 1965 INVENTOR A/fred .D. bk/15m United States Patent ware Filed Dec. 13, 1963, Set-.No. 330,297 6 Claims. (Cl. 313-239) This invention relates to a support means and more particularly to a rugged shield-like structure for supporting the mount assembly of an electron discharge device.

A very important consideration in the fabrication of electron discharge devices is the provision of sufiicient structure for adequately positioning and supporting a mount assembly upon a stem member.

For example, in cathoderay tube construction, the mount structure embodying the electron gun structure, contained within the neck portion of the tube, is conventionally supported on a wafer type stem by two or more support leads extending from the stem. These leads are bondingly connected, in spaced relationship, to the bottom grid element of the electron gun assembly or to the stud connecting the grid to a ceramic support rod. The bottom or first grid element, containing the associated cathode structure, must be spaced sufficiently from the stem wafer to allow for insertion of the heater into the cathode sleeve and facilitate subsequent consummation of the heater and cathode Welds to their respective leads. This spacing requires the mount support leads to be of commensurate length. These support leads, being integral continuations of the stern leads, are; of a gauge and length susceptible to bending when the mount structure is subjected to sudden impact shock. Any. deformation of these.

support leads from their intendedangle of support allows thegun structure to shift position within'the neck of the tube. This. alters the intended operational orientation of the electron gun with reference to: the desired impingement of the electron beam on the opposite disposed cathodoluminescent screen. Successive shocks can actually tear the mount from the stem. In cases of lesser shock or continued vibration repetitive shifting of the gun mount structure results in flexure of the support leads. This causes stress to be imparted to the glass stem'beads surrounding the leads with resultant fracturing of the glass whereby particles of glass are loosened. The movement of these loose particles within the tube aggravate tube failure by damaging the phosphor screen.

i In certain instances,spurious electrons and sublimation products emanating from the lower portionof the cathode and the heater tend to migrate to the interior surfaces of the stem wafer and neck portion of the tube thereby promoting aggravating leakage conditions.

Accordingly, it is an object of the invention to reduce the aforementioned disadvantages and to provide an improved mount supporting and shielding structure for an electron discharge device.

A further object is to provide arugged mount supporting structure that is formed to withstand acute shock and vibration.

A still further object is to provide a rugged electron gun supporting structure which facilitates the production of an improved cathode ray tube and to simplified construction method-s for the same.

The foregoing objects are achieved in one aspect of the invention by the provision of a substantially metallic shell-type frustum shaped member of which portions of the larger circumference are spacedly bounded to a plurality of wafer disposed stem leads while the smaller circumference is fixedly attached to the bottom electrode of the mount structure to be supported. Discrete openings along the larger circumference of the member al 3,231,777 Patented Jan. 25, 1966 low access to the interior and provide insulative spacing for those stem leads not bonded to the member.

For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the accompanying drawings in which:

FIGURE 1 is a top view looking downward showing the horizontal layout of the stern leads with reference to the mount support structure; and

FIGURE 2 is a side view showing the vertcial orientation of support structure with reference to the stem and mount.

There is shown in FIGURE 1 and 2 a wafer type stem 11 as used in certain types of cathode ray tube constructions. The stem conventionally comprises a .circular wafer 12 of a ceramic or glass material having a plurality of stem leads 13 embedded therein and protruding therethrough in an equi-spaced circular pin arrangement. Mounted thereupon is a metallic shell-type supporting member 41 to which is fixedly attached the bottom electrode or first grid 45 of a mount structure 49, partially shown in FIGURE 2.

The mount structure is built or supported upon the first grid (G1) electrode 45. Several insulative glass support rods, of which 48 is an illustrative example, are longitudinally oriented to provide spaced positioning and alignment for the several electrodes comprising the gun structure. The first grid 45 is affixed to support rod 48 by an exemplary stud 50. Likewise, the second grid 46 (G2) electrode is attached to the support rod by exemplary stud 51. In similar fashion, the remaining electrodes, which are not shown, are conjunctively integrated to form the complete mount structure supported by the first grid electrode 45.

In greater detail, the particular stem illustrated has fourteen leads, but the number of leads and the diameter of the wafer will vary according to the generic tube classification and intendedusage. The structure of the stem is strengthened by the formation of a plurality of ceramic or glass 'beads 15 integral to the wafer and disposed to cont-iguously encompass each of the leads on the internal portion 17 thereof adjacent the interior surface 19 of the Wafer 12. The external portions 21 of the leads 13 provide means for discrete electrical connections and compatible socket anchorage. Although not shown, a cathode ray tube stem usually contains an axial exhaust tubulation affording means for evacuating the tube of gases during processing. Since this tabulation has no bearing on the current invention, its designation is eliminated from the figures for simplification reasons.

In the tube herein considered certain of the plurality of stem leads 13, as shown in FIGURE 1, are specifically oriented for definite functions. For example, cathode lead 25 has an internal portion 17 of sufficient length, placement, and formation to adequately serve as a connection for the cathode, not shown.

Heater leads 26 and 27 are likewise of proper length, placement, and formation to function as connecting mediums for the heater, not shown.

'Further around the pin circle are leads 35 and 36 which have individual internal portions of sufficient length for connective purposes. with connector 39 serves as connective means for the G2 or second grid 46 of the mount structure 49. The inner portion of lead 36 is similarly affixed to a connector 40 for suitable connection to another electrode, not shown.

The'aforedescribed cathode, heater and other electrode leads 25, 26, 27, 35, and 36, which individually function as electrical connections for separate respective parts of Lead 35 in conjunction.

the mount structure 49, each have an eyelet or protective hat-like shielding structure 47 fixedly disposed adjacent the bead to enhance insulation by inhibiting the formation of electrical leakage paths resultant from sublimation.

The intervening elements of the pin circle, stein leads to 34 inclusive and 37 and 38 are rigid support leads having short internal upstanding portions 17 of substantially the same length. Disposed immediately within the pin circle defined by these leads and contiguously affixed to the individual leads is the aforementioned metallic shell-type supporting member 41.

This supporting member, being of a metal such as nonmagnetic stainless steel or the like, is shaped substantially as a frustum having a top perimetrical portion 53, a base perimetrical portion 57, and a flared shell defining a skirt portion 61 therebetween. The top perimetrical portion 53 is formed as an upstanding band adapted to encompass the G1 or first grid 45 of the cathode ray tube mount structure 49 and be securely attached thereto by a plurality of peripherally oriented welds. The skirt portion 61 and the base perimetrical portion 57 have discretely oriented insulative and entrance cutout segments 65 and 66 therein. These cutout segments provide access to the interior of the supporting shell-type member 41 to facilitate placement of the heater within the cathode and to effect consummation of the heater, cathode, and other connective welds to the respective stem leads that functionally are of a dilferent electrical potential. The cutouts are of sufficient size to allow adequate insulative spacing between the above-mentioned leads 25, 26, 27, 35, and 36 and the support shell 41.

The base perimetrical portion 57 is of an external circumferential dimension to fit contiguously within the pin circle for bonding attachment with a plurality of support leads 28 to 34 inclusive and 37 and 33 that are adaptive to common electrical connection. Since the metallic shell-type supporting member 41 is bonded to the first grid 45 any one of the support leads 28 to 34 or 37 or 38 may function as a G1 connecting lead. As previously mentioned these G1 support leads are electrically insulated from other leads 25, 26, 27, 35, and 36 of the pin circle that are of different electrical potential.

As shown in the figures, top perimetrical portion 53, which is formed as a substantially-upstanding band, has a vertical cleft therein which extends as a vertical slit 55 through the skirt and base portions 61 and 57 respectively. The purpose of this fissure in the supporting member 41 is to reduce the pick-up of induction heat by the member during tube processing. It is well to mention at this point that the supporting member is carefully batch processed and outgassed prior to assembly to reduce the need for excessive heat in this region during tube processing. The adjacency of the glass stem beads to the support structure makes excessive heat in the base perimetrical portion undesirable.

Although not shown, it may be desired to eliminate the cleft 54 from top perimetrical band 53 while retaining the slit 55 in the skirt and base portions. It is also evident that a plurality of clefts and slits either continuous or staggered could be utilized in keeping with the concepts disclosed herein.

As clearly illustrated in FIGURE 1, the support afforded by the G1 leads 28 to 34 and 37 and 38 is well distributed around the base perimetrical portion 57. The slit 55 and segment cutouts 65 and 66 create a plurality of bearing sections 69 in the base perimetrical portion 57. The base portion is circumferentially dimensioned and formed for positioning these arcuate bearing sections 69 in contiguous internal engagement with the respective G1 support leads of the pin circle. Bonding, as by welding, is effected between the support leads and the bearing sections at areas adjacent but spaced from the glass lead beads 15. These weld areas are oriented substantially i at or near the ends of the internal portions 17 of the G1 support leads 28 to 34 and 37 and 38.

While a shell-type support member 41 having the substantial shape of a conical frustum has been shown and described in this specification, a shape embodying a pyramidal frustrum may also be utilized with appropriate associated elements. Therefore, the term frustum as used in this specification is intended to include any geometric perimetrical manifestation.

Furthermore, utilization of the frustum shaped support as herein shown and described substantially positions the mount structure 49 in a vertical position relative to the plane of the stem 11 since the planes defined by the edges of the top perimetrical portion 53 and the base perimetrical portion 57 are substantially parallel. There may be instances when it is desired to have the mount assembly oriented in a nonvertical position relative to the plane of the stem, i.e. on an oblique angle thereto. This angular mounting is provided by using a support member shaped as a modified frustum wherein the planes defined by the edges of the top perimetrical portion and the base perimetrical portion are not parallel. Therefore, the term frustum as used in this specification is intended to include the aforementioned modifications thereof.

It is evident from the foregoing description, that in addition to providing rugged support, shell-type member 41 also provides shielding effects to reduce the transition of spurious electrons and sublimation products from the heater and cathode to the stem wafer and neck portion of the tube.

There is thus provided an improved mount supporting and shielding structure for an electron discharge device. The structure, while formed of simplified construction, effects an improved ruggedness to withstand acute shock and severe vibration thereby maintaining desired assembly alignment for optimum device performance.

While there has been shown and described what is at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

What is claimed is:

1. In an electron discharge device having a planar stem member containing a plurality of rigid support leads embedded therein, shielding means for supporting a mount structure thereon comprising:

a metallic shell-type member shaped substantially as a frustum having a top perimetrical portion, a base perimetrical portion and a skirt portion therebetween said top portion being substantially formed for bonding to a support portion of said mount structure, said skirt portion and said base portion having a continuous vertical slit therein, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion being substantially formed to provide for bonding to a plurality of said support leads adaptable to common electrical connection.

2. In an electron discharge device having a planar stem member containing a plurality of rigid support leads embedded therein, means for supporting an electrode of the mount structure thereon comprising:

a metallic shell-type member shaped substantially as a frustum having a top perimetrical portion, a base perimetrical portion and a skirt portion therebetween, said top portion being formed substantially as an upstanding band adapted to encompass said electrode of said mount structure for bonding thereto, said skirt portion and said base portion having a continuous vertical slit therein extending to said band, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion being formed with arcuate bearing sections to provide for bonding 3,231,777 6 to a plurality of said support leads adaptable to the first electrode of the mount structure thereon comcommon electrical connection. prising:

3. In an electron discharge device having a planar a metallic shell-type member shaped substantially as stem member containing a plurality of rigid support a frustum having a top perimetrical portion, a base leads embedded therein, means for supporting an elec- 5 perirnetrical portion and a skirt portion therebetrode of the mount structure thereon comprising: tween, said top portion being formed substantially a metallic shell-type member shaped substantially as as an upstanding band adapted to circumferentially a frustum having a top perimetrical portion, a base encompass said first electrode of said mount strucperimetrical portion and a skirt portion therebetween, ture for bonding thereto, said skirt portion and said said top portion being formed substantially as an up- 10 base portion having a continuous vertical slit therein standing band adapted to encompass said electrode of said mount structure for bonding thereto, said skirt portion and said base portion having a continuous vertical slit therein extending to said band, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion having discretely distributed bearing sections formed to provide for extending to said band, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion being circumferentially dimensioned and formed for contiguous internal engagement of said pin circle to provide bearing sections for bonding to a plurality of support leads adaptive to common electrical connection.

bonding to a plurality of said support leads adaptable to common electrical connection. 4. In an electron discharge device having a planar stem member containing a plurality of rigid support leads embedded therein, means for supporting an electrode of the mount structure thereon comprising:

a metallic shell-type member shaped substantially as a 6. In a cathode ray tube having a planar stem member containing a plurality of rigid support leads embedded therein in the form of a pin circle, means for supporting the first electrode of the mount structure thereon comprising:

a metallic shell-type member shaped substantially as a frustum having a top perimetrical portion, a base frustum having a top perimetrical portion, a base perimetrical portion and a skirt portion therebetween, said top portion being formed substantially as a band adapted to circumferentially encompass said electrode of said mount structure for bonding thereto, said band having at least one vertical cleft therein, said skirt portion and said base portion having a continuous vertical slit therein extending from a cleft in said band, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion having discretely formed bearing sections to provide for bonding to a plurality of said support leads adaptable to common electrical connection.

perimetrical portion and a skirt portion therebetween, said top portion being formed substantially as an upstanding band adapted to encompass said first electrode of said mount structure for bonding thereto, said band having a vertical cleft therein, said skirt portion and said base portion having a continuous vertical slit therein extending from said cleft in said band, said skirt portion and said base portion having discretely oriented insulative and entrance cutout segments therein, said base portion being circumferentially dimensioned and formed for contiguous internal engagement of said pin circle to provide bearing sections for bonding to a plurality of support leads adaptive to common electrical connection.

5. In a cathode ray tube having a planar stem member containing a plurality of rigid support leads embedded therein in the form of a pin circle, means for supporting No references cited.

JOHN W. HUCKERT, Primary Examiner.

DAVID J. GALVIN, Examiner. 

1. IN AN ELECTRON DISCHARGE DEVICE HAVING A PLANAR STEM MEMBER CONTAINING A PLURALITY OF RIGID SUPPORT LEADS EMBEDDED THEREIN, SHIELDING MEANS FOR SUPPORTING A MOUNT STRUCTURE THEREON COMPRISING: A METALLIC SHELL-TYPE MEMBER SHAPED SUBSTANTIALLY AS A FRUSTUM HAVING A TOP PERIMETRICAL PORTION, A BASE PERIMETRICAL PORTION AND A SKIRT PORTION THEREBETWEEN SAID TOP PORTION BEING SUBSTANTIALLY FORMED FOR BONDING TO A SUPPORT PORTION OF SAID MOUNT STRUCTURE, SAID SKIRT PORTION AND SAID BASE PORTION HAVING A CONTINUOUS VERTICAL SLIT THEREIN, SAID SKIRT PORTION AND SAID BASE PORTION HAVING DISCRETELY ORIENTED INSULATIVE AND ENTRANCE CUTOUT SEGMENTS THEREIN, SAID BASE PORTION BEING SUBSTANTIALLY FORMED TO PROVIDE FOR BONDING TO A PLURALITY OF SAID SUPORT LEADS ADAPTABLE TO COMMON ELECTRICAL CONNECTION. 